An X-ray CT (Computed Tomography) apparatus is an apparatus for imaging an inside of a subject by scanning the subject using X-rays and computer processing acquired data.
Specifically, the X-ray CT apparatus exposes X-rays to a subject multiple times from different directions, detects the X-rays transmitted through the subject by an X-ray detector, and acquires a plurality of detected data. The acquired data is A/D converted by a data acquisition system, and then transmitted to a console device. The console device performs preprocessing on the detected data to create projection data. The console device then performs reconstruction processing based on the projection data, and creates tomographic image data, or volume data based on a plurality of tomographic image data. The volume data is a data set representing a three-dimensional distribution of CT values corresponding to a three-dimensional domain of the subject.
The X-ray CT apparatus is able to perform MPR (Multi Planar Reconstruction) display by rendering the volume data in an arbitrary direction. Cross section images displayed by MPR (hereinafter, refer to as “MPR images”) include, for example, an axial image, a sagittal image, and a coronal image. The axial image represents a cross section orthogonal to a body axis, the sagittal image represents a cross section dividing the subject into right and left halves along the body axis, and the coronal image represents a cross section dividing the subject into ventral and dorsal halves along the body axis. An image of any arbitrary cross section (oblique image) of the volume data is also included in the MPR images.
In CT fluoroscopy (Computer Tomography Fluoroscopy) using the X-ray CT apparatus, images are created in real-time by shortening both an acquiring rate for the detected data and time required for reconstruction processing. This CT fluoroscopy is used in a case, for example, when a relationship between a puncture needle and a body site from where a specimen is collected is verified during a biopsy procedure.
When a biopsy is performed with respect to a subject while referring to MPR images, which are created based on volume data obtained by CT fluoroscopy, for example, scanning and puncturing may be performed in alternative manner. Specifically, first, MPR images of a subject are obtained by CT fluoroscopy. Doctors and the like perform puncturing while referring to the MPR images. At the time, for example, in order to verify a relationship between a puncture needlepoint and a body site from where a specimen is collected, the CT fluoroscopy is again performed when puncturing is done to some extent. The doctors and the like further proceed to the puncture as referring to MPR images obtained by the later CT fluoroscopy. The above operations are repeated until the biopsy is completed; thereby the biopsy can be performed without fail.
In addition, when a biopsy is performed by CT fluoroscopy, a puncturing plan may be made in advance. The puncturing plan is information including a preliminary set insert passage of a puncture needle with respect to a subject (hereinafter, the passage may be called “planned passage”). The puncturing plan is set, for example, by drawing a planned passage, with the help of equipment for instruction input such as a mouse, or the like, on the CT images obtained in advance before the CT fluoroscopy is performed. The doctors and the like perform puncturing with respect to the subject as referring to the CT images (planned images) indicating the planned passage and the MPR images, which are created based on volume data obtained every time X-ray scanning is performed.